Development of ZnTe layers using an electrochemical technique for applications in thin-film solar cells

Zinc telluride layers were grown by an electrochemical technique using acidic and aqueous solutions containing ZnCl2 and TeO2. The layers were deposited on glass/fluorine-doped tin oxide substrates using a two-electrode system. The deposited ZnTe layers were characterized using x-ray diffraction, x-ray fluorescence, Raman spectroscopy, optical absorption, photoelectrochemical cell measurements, scanning electron microscopy and 3D-atomic force microscopy (3D-AFM) for the structural, optical, electrical and morphological properties. The electrodeposited ZnTe layers grow as columns, and have cubic crystal structure, the band gap in the range of (2.00–2.20) eV and p-type electrical conductivity. Surface morphology studies using SEM indicate the presence of two types of material clusters varying in size up to ~125 nm. 3D-AFM studies with higher magnification show that the material tends to grow as columns with different sizes leaving gaps in between in some areas.